In recent years, in addition to a chemical synthesis method, synthesis of a substance using an organism or an enzyme has been started to be conducted in an industrial level. Synthesis of a substance by an organism or an enzyme enables reduction of energy in synthesis compared to a chemical synthesis method, and also enables synthesis specialized in a specific structure of a compound having an optical isomer. Meanwhile, improvement of the productivity is one of important issues in industrial production of a useful substance by a microorganism. Conventionally, breeding of a production microbe through genetic approaches such as mutation have been conducted as an approach to improve the substance productivity of a microorganism. In particular, recently, more efficient microbiological production of a useful substance using a recombinant technique etc. has been drawing attention due to the development of microbial genetics and biotechnology.
So far, Rhizopus, a filamentous fungus, has been disclosed as a microorganism which can be used in the production of lactic acid (Patent Documents 1 to 3). However, in a fungus of Rhizopus, examples of the study on recombinant techniques etc. are few because genetic background was not clear, introduction of a molecular genetic approach was late, and isolation and maintenance of a monoclonal strain is expected to be difficult since a fungus of Rhizopus has multinucleated cells. Though a 1dhA promoter (Patent Literature 1, Non Patent Literature 1), a pgk1 promoter (Patent Literature 2, Non Patent Literature 2), a pgk2 promoter (Patent Literature 3), pdcA and amyA promoters (Non Patent Literature 2), tef and 18Sr RNA promoters (Patent Literature 4) etc. are reported as promoters necessary for the transcription of a gene in a fungus of Rhizopus, the intensity of expression of these promoters has not necessarily been examined comprehensively and promoters and microorganisms which achieve even higher productivity are required to reduce the production cost in industrial production.    [Patent Document 1] U.S. Pat. No. 6,268,189    [Patent Document 2] International Publication No. WO 2001/73083    [Patent Document 3] International Publication No. WO 2001/72967    [Patent Document 4] U.S. Unexamined Patent Application Publication No. 2010/112651    [Non Patent Document 1] Applied Microbiology and Biotechnology (2004) vol. 64:237-242    [Non Patent Document 2] Archives of Microbiology (2006) vol. 186:41-50